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//============================================================================
// Name : ZKTest.cpp
// Author : Michael P Smith (AKA, Krin), Under Codethink .Ltd
// Version : 0.0.1
// Copyright : Your copyright notice
// Description : a first attempt at making a zookeeper client in C
//============================================================================
#include <iostream>
#include <thread>
#include <mutex>
#include <string.h>
#include <errno.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "zookeeper.h"
using namespace std;
static zhandle_t *zk;
static const clientid_t *session_id;
struct String_vector list_of_children = {0};
int timeout = 3000;
int responseCode = 0;
std::mutex mutex_lock;
void safeShutdown(zhandle_t *zzh);
void watcher(zhandle_t *zzh, int type, int state, const char *path,
void *watcherCtx);
void discoverChildren(const char* path);
int main(int argc, char **argv)
{
session_id = NULL;
char* p;
cout << "Initialising Zookeeper" << endl; // prints !!!Hello World!!!
zk = zookeeper_init("localhost:2181", watcher, timeout, session_id, NULL, 0);
while (!zk)
{
}
p = strtok(NULL, " ");
std::cout << "starting authentication" << std::endl;
zoo_add_auth(zk, "digest", p, p ? strlen(p) : 0, NULL, NULL);
while (zoo_state(zk) == 0)
{
}
std::cout << "authentication step done" << std::endl;
while (zk)
{
/*
* mutex used to make the main program loop wait until there is feedback
* from zookeeper. initially locks, then loops around. thread cannot lock
* again until the current lock has been unlocked.
*/
mutex_lock.lock();
/*
* debug test to show that the loop does not continue until watcher
* is called
*/
std::cout<<"loop locked"<<std::endl;
}
safeShutdown(zk);
return 0;
}
///////////////////////////////////////////////////////////////////////
/// END OF MAIN ///
///////////////////////////////////////////////////////////////////////
void safeShutdown(zhandle_t *zzh)
{
if (zzh)
{
cout << "closing Zookeeper connection" << std::endl;
zookeeper_close(zzh);
zk = 0;
}
}
static const char* state2String(int state)
{
if (state == 0)
return "CLOSED_STATE";
if (state == ZOO_CONNECTING_STATE)
return "CONNECTING_STATE";
if (state == ZOO_ASSOCIATING_STATE)
return "ASSOCIATING_STATE";
if (state == ZOO_CONNECTED_STATE)
return "CONNECTED_STATE";
if (state == ZOO_EXPIRED_SESSION_STATE)
return "EXPIRED_SESSION_STATE";
if (state == ZOO_AUTH_FAILED_STATE)
return "AUTH_FAILED_STATE";
return "INVALID_STATE";
}
static const char* type2String(int type)
{
if (type == ZOO_CREATED_EVENT)
return "CREATED_EVENT";
if (type == ZOO_DELETED_EVENT)
return "DELETED_EVENT";
if (type == ZOO_CHANGED_EVENT)
return "CHANGED_EVENT";
if (type == ZOO_CHILD_EVENT)
return "CHILD_EVENT";
if (type == ZOO_SESSION_EVENT)
return "SESSION_EVENT";
if (type == ZOO_NOTWATCHING_EVENT)
return "NOTWATCHING_EVENT";
return "UNKNOWN_EVENT_TYPE";
}
void watcher(zhandle_t *zzh, int type, int state, const char *path,
void *watcherCtx)
{
mutex_lock.unlock();
if (type == ZOO_SESSION_EVENT)
{
std::cout<<type2String(type)<<std::endl;
if (state == ZOO_CONNECTED_STATE)
{
std::cout<<state2String(type)<<std::endl;
zoo_create(zk, "/test","my_data",7, &ZOO_OPEN_ACL_UNSAFE, ZOO_EPHEMERAL, NULL, 0);
zoo_create(zk, "/childTest","my_data",7, &ZOO_OPEN_ACL_UNSAFE, 0, NULL, 0);
zoo_exists(zk, "/test", true, NULL);
/*zoo_exists tests if a node exists, and if the 3rd argument is non 0 sets a watch
* that watch is triggered upon any change to the file specified in arg 2
* argument 1 is the zookeeper session to make the request too
* */
responseCode = zoo_get_children(zk, "/childTest", true, NULL);
discoverChildren("/childTest");
/*
* as zoo_exists but watches children of the specified node.
* argument 4 is a string that can be used to return the path of child nodes.
*/
session_id = zoo_client_id(zzh);
return;
}
else if (state == ZOO_AUTH_FAILED_STATE)
{
std::cout<<state2String(type)<<std::endl;
safeShutdown(zzh);
}
else if (state == ZOO_EXPIRED_SESSION_STATE)
{
std::cout<<state2String(type)<<std::endl;
zk = zookeeper_init("localhost:2181", watcher, timeout, session_id, NULL,
0);
}
}
else if (type == ZOO_DELETED_EVENT)
{
std::cout<<type2String(type)<<std::endl;
zoo_exists(zk, path, true, NULL);
}
else if (type == ZOO_CHILD_EVENT)
{
std::cout<<type2String(type)<<std::endl;
discoverChildren(path);
}
else if (type == ZOO_CHANGED_EVENT)
{
responseCode = zoo_exists(zk, path, true, NULL);
std::cout<<type2String(type)<<std::endl;
}
else if (type == ZOO_CREATED_EVENT)
{
responseCode = zoo_exists(zk, path, true, NULL);
std::cout<<type2String(type)<<std::endl;
cout << "creation of watched node detected" << std::endl;
}
}
void discoverChildren(const char* path)
{
struct String_vector list_of_children_discovered = {0};
cout << "discovering children"<<path<< std::endl;
zoo_get_children(zk, path, true, &list_of_children_discovered);
zoo_exists(zk, path, true, NULL);
if(list_of_children_discovered.count)
{
for (int i = 0; i < list_of_children_discovered.count; i++)
{
string child_to_add = path;
child_to_add += '/';
child_to_add += list_of_children_discovered.data[i];
const char* end_result = child_to_add.c_str();
discoverChildren(end_result);
}
deallocate_String_vector(&list_of_children_discovered);
}
}
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